Turbine governing apparatus



Oct. 26, 1943. M. GoT'rLlEB v 2,332,910

TURBINE GOVERNING APPARATUS Filed March 5, 1942 INVENTOR i nmous GoT-russ;

ATTORNEY Patented Oct. 26, 1943 rottami emfrlmm username' jf; .I Manaus Garnier,,Irhilaaelphiaat .assigner` t ,Westinghouse Electric & Manufacturing ,0cm-

Pennsylvania pany, East Pittsburgh, lf-au a j-corporation lof accordance with the" present invention, injury to the apparatus in the `respects indicated for 'any reason is preferably'avoided by having the stem comprisedby rst and secondparts with 'a spring disposed between the parts, the vfirst part carrying and guiding the valve and thesecond part being operated upon by the speed-responsive means. A further object of the invention is to provide apparatus having these improved features.

A further object of the invention -is to provide I apparatus of the character described having impro-ved means for effecting speed compensation.

These and other objects are effected by the in I vention as will be apparent from the following Ildescription-and claims taken in connection with the accompanying drawing, forming a part of this application, in which:

Fig. 1 is a sectional View of the improved lgovernor shown diagrammatically in relation to a prime mover;

Fig. 2 is a detail sectional View showing the valve and the improved stem construction; and I Fig, 3 is a fragmentary sectional view of a modied form.

In the drawing, there is shown a turbine Ior prime mover I0 having an admission valve II controlled by pressure-responsive means I2. Fluid under pressure for `the .pressure-responsive means is provided `by the transformer, at I3,

the means for applying edge jor rim to cooperating with the seat Jit to denne arr-escape ermee bennes a vaivepre's'- sure area subject topressure itheeine'rosatispace lr, The 'valve reis-connected to one fee-'deems stem construction, 1art1, andere eener erre zei 'melanger ccoperateswith any suitable means applying force thereto dependent upon lt 'or prime "moverspeecl 'and *in -o'psed relatie f the force of chamber'pressure-applied to the valve pressure area.

As shown, .the 1inea-ns providing aforo@ 1dependent'n'pon speed comprises arotarfjf member verseiy van; respect to the-asis of rotation of the' fstructurecaand it has a -central `raarst- `transnf1`itting portion ZBfrmwhich force is transmitte-d mrougnme -thrusmransmitang means, at interne i'cwer endefthe stem construction,

The thrust-transmitting-means,preferably, includes a seat member 28 `having a cavity 29 for a-ball '30 engaging -tne'bottom of the cav-ity and the lowerlend of the stein construction. These'at member 28 lhas lan Aannular seat `3'. for the lower end fof the -lo'ad 'spring 33 whose upper end is engaged by a follower 34 capable of adjustment upwardly and downwardly by means lof the nut 39 of the speed changerapparatus. I I I l"-Ihe stem construction, at.2l.,comprises`outer and-inner members 4I :and 42. The valve -I Sis alt.-

tached to the upper-,end of theouter member 4I sofas -to constitute, in eiect, `a `part thereof and the lower -ndof the inner` member 42 is engaged by Ethe thrust-transmitting means, at 21. A rst pair 'of opposed abutments 43 and 44 are carried, respectively, by the outer Tand inner members, and the Iouter and` inner members have second pair of'voppos'e'd abutments 45 A.and 4B located between tlierst pair of I'abutments and .the cup valve vand controlled by suitable means acting in response between which vis disposed the yieldable means oi spring '"41. Normally, the force of the springIIl'I is,l effective to vmaintain the abutments 43 and 44 incontacts thatlth'rus't transmitted to tiie'lower end of the stem construction is eifectiveto acton the cup valve `to modify the fluid .pressurein 'the space orfchamber LI 5in accordance with the force; however; ishould, for any reason, an excessive force be applied tothe structure `including "the thrust-transmitting vlm'ean'sat 21, the stem construction, lat2^II, the valve` I9, and the seat of the latter, Ainjury Ito 'any oi `all 'ofc these features 2 I f' r 2,332,910

of` construction willbe avoided due to the yieldabley means or spring 41, the latter operating,

shell 52 forming a part of the outer element 4.I",1V .Y

of the stem constructioniand enclosing the yield-` able means or spring 4I. As the valve I9'i's alig ned"`` with the shell 52 and attached tothe upper end of the latter and as the guide 5U is arranged at right angles .to the plane of the seat I8, it will be apparent that the cylindrical shell 52 confines the valve I9 to movement in a direction normal to the seat. In addition to the guide 5| provided by the; bore, a plug 54 inserted in the lower end of the- L bore provides .a guide 55 for the sleeve portion5`l of the stem elementg 4I, `the sleeve portion 5l Vhavingr telescopic relationwith respect to the stem vor rod portion 58 of the inner stem elementfi. Thus, it will be seen that the outer stemelement 4| is effectively guided by the guides 5I and'55 cooperating with the portions 52 .and 57,01 the outer stem element 4i; and, as the stem 561 of the inner stem` element 42 has telescopic' relation with respect to the tubular portion 51- of the outer element, the inner element will be eiectively guided by the outerelement. Thus, there is provided a structure which affords the required iiexibility to protect it against excessive applied forces and which at the same time assures of absence oi any play .which would impair vthe accuracy of the governor, e

As shown, speed compensation for load change is provided by the delayed application oi changes in pressure in thespace` yl5 to the chamber 5ba, to which is exposed the piston orV pressure area 55 provided by the upper portionof the stem structure, at 2i, and arranged in opposedrelation tothe area oiythe cup valve i5 exposed to ypressure of the space I5.

' The pressure space I5 is connected by an orifice `51' to the chamber 58 rendered expansible` by means of ther bellows 55, the interior spring` 60, and the spring abutment 5I constituting a closure i'or the lower end o the bellows. A, passage 62, preferably including an orice 63, provides for communication of `the interior` of the bellows with the atmosphere. The expansible chamber 53 is connected by a passage 63 with the chamber 5ta for the pressure area 5G.l f 'l Operation vof the compensating apparatus is as follows: l Assuming a change in load, the speed changes temporarily due to loa'd change and then the compensator comes into` play'to compensate the change in speed for the changeinload.V AA.

change in load and accompanying change: in speed results in change in force applied to the lower end of the stem construction, at ZI, Vand this brings about, due to the cup yalveIS and its seat it, a change in pressure in thespace I5 to `operate lthe pressure-responsive means Y,I2-1, to change the admission of motive iiuid` to; the prime mover Ito suit the change in load. The lastrnentioned step would bethe ffinal one for conventional or uncompensated governor operation'wherein a change in speed from no load'to Vfull load. is" inherent. With 'the compensator,

pressure change in the space I5 is followed by delayed ychange in ,pressure in thechamben occurring on account of the orice 5]. and the bellowsV 59, and the delayed change bringing about further adjustment so as to reduce the vspeed change due to load change. With the pressure area 56 equal to the cup valve area, follow- Y ing a change in load, the parts would come to an equilibrium position with the fluid pressure forces acting on the stem construction in equilibrium Aand 'with theforce of the ilyweights balancing the'forcje dueto the load spring, that is, the governor would operate isochronously, motive fluid being admitted to the turbine so as to operate the latter at the same speed from no load Ato ull'load.

InFig. 3, instead of the spring being incor- -porated in the valve stem structure to limit contact pressure of the valve I9 with the seat I8, the

same result is achieved by providing an element GS having the port Il and the seat I8. The element has a sliding fit with respect to an opening E@ formed in the structure 48, and it is biased toward vthe cup valve portion IS of the valve `element by means of the spring tl, movement due to forcey of c the spring v being limited by the shoulder 58 cooperating with the seat Si).

Whenever the contact pressure of the Valve element with the relement 55 tends to exceed a value determined by the spring Ei'Lthe latter yields and permits movement of the element G5, with the result that, as hereinbefore pointed out, various parts of the construction are protected againstl injury, t

While the invention has been .shown in several forms, it will be obvious to those skilled in the vart that'it is not so limited, butis susceptible of various other changes and modifications without departing from the spirit thereof, and it is desired, therefore, that only such limitations shall be placed thereupon as are specifically set forth .in the appended claims.

Ation with respect to the port and cooperating withthe seat;v means including a stem structure having its upper end connected to the valve; a force-transmitting element engaging theA lower end of the stem structure; means responsive to speed of the prime mover for applying forceto said element; said stem structure including inner andouter elements and the outer element comprising an upper portion of larger diameter and a lower portion of smaller diameter joined so that the upper portion defines a pressure area 'about' the lower portion and in opposed relation to therarea of the cup valve exposed to space pressure; said upper portion having upper and lower abutments; means connectedto the upper end of the inner element and providing upper and lower abutment-s arranged between the rst abutments; a spring between the upper abutments and normally serving to maintain the lower abutments engaged; guide means for the stem structure and providing a chamber to which said piston area is exposed; means dening an expansible chamber including a bellows element closed at its inner end ,and having its interior open to the atmosphere; a spring acting on the bellows element in such a direction as to tend to diminishfthe volumefofthe expansible chamber;

means including an orifice for connecting said space to the expansble chamber; and a passage for connecting the expansible chamber to the chamber for said pressure area.

2. In a prime mover having an admission valve controlled by pressure-responsive means, means providing an enclosed space for supplying fluid under pressure to the pressure-responsive means; an orice for supplying Huid froma suitable pressure source to the space; said means having an escape port for the space and providing a seat encompassing the port; a valve in covering relation with respect to the port and cooperating with the seat; means including a stem structure having its upper end connected to the valve; a force-transmitting element engaging the lower end of the stem structure; means responsive to speed of the prime mover for applying force to said element; said stem structure including an upper portion of larger diameter and a lower portion of smaller diameter formed so that the upper portion defines a pressure area about the lower portion and n opposed relation to the area of the cup valve exposed to space pressure; guide means forthe stem structure and providing a chamber to which said pressure area is exposed; means defining an expansible chamber and including a bellows closed at its inner end and having its interior open to the atmosphere; a

`spring acting on the bellows in such a direction as to tend to diminish the volume of the ex pansible chamber; means including an orifice for connecting said space to the expansible chamber; and a passage for connecting the expansible chamber to the chamber for said pressure area.

MANIOUS GOTTLIEB. 

